In a variety of medical procedures it is required to provide fast connecting means for connecting fluid transferring tubes to one another, for connecting tubes to branching devices and to different medical devices, as well as to a variety of flow control valves, etc.
For these and many other purposes, a variety of luer-type connectors are commonly utilized, which connectors provide on the one hand fast connecting and disconnecting, and on the other hand, provide reasonable reliability and security which is a critical requirement of such connectors to prevent un-intentional disconnection between the components, which under certain circumstances may be fatal for the patient or for the medical staff which may be exposed to contaminated body fluids. Still another problem which may occur in a connector non-tightly coupled is entry of air into the system which may be fatal.
Luer-type connectors are thus commonly in use. Various designs of luer-type connectors are available in which a tapered nozzle of a male-component is dimensioned to snugly, frictionally fit into a tapered socket female-component of the fitting, with a collar member rotatably retained over the male component and adapted for screw coupling with an annular threaded flanged portion of the female-component.
A variety of luer-type connectors are available and special consideration has been given to increased connecting force which at times may be required, e.g. to facilitate high pressure fluid flow through the connecting and to prevent ingress of air into the system or, for extra precaution to prevent loss of high risk fluids such as contaminated body fluids. However, excessive rotational force applied to the collar may eventually lead to disengagement of the collar from the male-component, entailing decoupling of the connection which may result in a hazardous outcome.
In particular, the problem of disengagement of the collar from the male-component may occur while transferring fatty which have a lubricating effect on the coupling, or even in case of unintentional excessive force applied to the collar, e.g. in case of stress of the medical staff.
Several attempts have been made to prevent disengagement of the rotatable collar from the male component. U.S. Pat. No. 5,047,021 discloses in FIGS. 2a, 9 and 10 some prior art arrangements in which the male-component is formed at a rear end of its nozzle with a radial abutting shoulder adapted for arresting a corresponding abutting ridge of the collar, thus preventing further axial displacement of the collar over the nozzle once said abutting walls engage one another. The drawback of such an arrangement is that no frictional resistance exists between the rotatable collar and the nozzle member whereby essentially all the fastening force is directed to screw coupling between the collar and the female-component, which may result in mechanical fracture of the components.
U.S. Pat. No. 5,620,427 discloses in FIGS. 8a-8c an arrangement in which the male-component is formed at a rear end thereof with an inclined surface adapted for engaging a corresponding inclined surface of the collar, whereby excessive tightening of the collar is supposed to cause a hard stop and prevent disengagement of the collar from the male-component during engagement of said inclined surfaces. However, a serious drawback of this arrangement resides in that excessive force will eventually cause the inclined surface of the collar to slip over the inclined surface of the nozzle until disengagement of the collar from the male-component, leading to some undesirable results.
It is thus an object of the present invention to provide a luer-type connector in which the above-referred to disadvantages are significantly reduced or overcome.
A further object of the invention resides in providing an improved male-component of a luer-connector in which the collar is prevented from disengaging therefrom.